Air conditioning apparatus



June 29, 1937. A KE Y 2,085,028

' AIR CONDITIONING APPARATUS Original Filed July 20, 1932 Patented} June 29, 1937 AIR. CONDITIONING APPARATUS Gilbert A. Kelley, Dayton, Ohio, assignor, by

mesne assignments, to General Motors Corporation, a corporation or Delaware Application July 20, 1932, Serial No. 623,531 Renewed September 30, 1936 9 Claims.

This invention relates to refrigeration and more particularly to an apparatus for conditioning air or selectively removing a constituent from a gas.

Heretofore it has been customary to condition air, or .to remove a constituent. from a gas, by contacting the air or gas with a solution or liquid. capable of removing moisture from the air, or a constituent from the gas, and by regen- 19 crating the liquid by evaporating or heating the liquid to remove moisture or the constituent. An

object of this invention is to provide an apparatus for, accomplishing the foregoing results description, reference'being had to the accomstituent isito be removed, is contacted with a panying drawin wherein apreferred form of the present invention is clearly shown.

In the drawing:

The figure shows, partly in cross-section and partly in elevation, an apparatus for practicing this invention.

In the practice of this invention, the air to be conditioned. or the gas from which the conhygroscopic liquid, or a liquid having a selective amnity for the constituent to be removed, the

contact being accomplished at a relatively low temperature, so that moisture is removed from 'the air or the constituent is removed from the gas. The liquid is regenerated by heating it to. a relatively high temperature and contacting the heated liquid with a stream of air, or gas,

to remove moisture, or the constituent, from the liquid. In the particular embodiment shown,

v the air or gas is circulated either 'from the room ill, or from a conduit ll leading from the outside, or both, by means of a blower I2 and the stream tact tower or apparatus I3 where it comes in contact. with a hygroscopic liquid, or with a liquid t r u h. one or more conduits It or ha 8 mgv d, and thereafter the air or gas is discharged 15' which of air or .gas is forced through the conmini t for a constituent to berean y 'higher degree than the carry the air or gas to the desired place of use, in this particular embodiment being the room .il'i and other similar enclosures.

The hygroscopic liquid is regenerated by heating the liquid in the heater l6, and while the liquid is in a heated condition, it is contacted. with a stream of air or gas in the concentrating contact tower I? where moisture, or the constituent, -is removed by air or gas passing through the tower. In this particular embodiment in which air is being conditioned for use in a building, the air which removes the moisture from the liquid is taken from the outside of the building through the conduit i8, is forced by the fan l9 through the tower H and is discharged through the conduit 20 to the outside of the building.

In the preferred embodiment, the hygroscopic liquid is circulated in a closed cycle in a portion of which the liquid is cooled to a relatively cold temperature, and while in that relatively low temperature it is contacted" with the air to be conditioned. Thus a sump 2| is provided for holding a main body of liquid, this liquid having such a water vapor pressure that when cooled to the desired temperature it'imparts to the air the proper temperature and relative hll-z midity. A portion of the liquid is circulated by means of the pump 22 from and to the main body of liquid in sump 2| through a cooler 23 where the liquid is cooled either by city water, air, or by mechanical refrigeration, and thereafter it is forced through the distributing head 24 and passes on to the contact tower l3 where it imparts the correct temperature and relative. humidity to the air passing through the tower, the liquid returning through the pipe 25 tothe sump 2|. g

The liquid is regenerated also in a closed circulating cycle, which in this .particular embodiment is partly separate from the air conditioning liquid cycle. Thus a portion of the liquid is forced by the ,pump 28-from and to the main body of liquidin sump 2i through the heater l6 where it is heated to a relatively high temperatureand passes on tothe distributing head 21 for distribution and. gravitational flow through the contact tower H where it comes in contact, in a heated condition, with a stream of air independent of theair being conditioned and returns in a concentrated condition through the pipe 28 to the sump 2|. By this construction it is possible to concent ate the liquid to a much concentration of the main body'of liquid in the sump 2|. The rate of flow through the concentrating cycle is so controlled that it maintains the main body of liquid at the proper air conditionina'concentration.

.5 Automatic controls are provided for the appathe temerature and/or relative humidity in the room l rises about the desired limit then the,

motors 30 and 3! are caused to operate until such a time as the temperature and/or relative l5 humidity are reduced to a lower desired limit. Controls of this type are well known and hence are not further described. An automatic control is also provided to maintain the liquid in the sump 2| at a predetermined degree of con- 20 centration or regeneration such that, when tproperly cooled, it imparts the desired temperature and relative humidity to the airpassing tower i3. To this end means for controlling'the removal of moisture or the constituent, 25 from the liquid are provided, these being automatically responsive to the degree of concentration of the main body of liquid. Thus a portion of the liquid flowing through the pipe 32 is by-passed through the pipe 33 to a control chamber 34 provided with an overflow pipe 35 which returns the overflow to the sump 2i. By

a continuous flow through the pipes 33 and 35,

the liquid in the chamber 34 is maintained at substantially the same concentration as the 35 liquid in the sump 2| or at a concentration representative thereof. A hydrometer control 36 is placed in the chamber 34 which controls the action of the heating element or burner 31, so that the temperature of the liquid circulating in the 40 pipe 38 is increased or decreased to govern the drying action taking place-in the'tower i'lin such a manner that the proper concentration of the liquid in thesump 2! is maintained. Thus if the liquid in the sump 2! tends to become too 45 dilute, the contact arm 39 operated by. the hydrometer float, contacts with the contact 40, and the gas control valve 4| is opened to intensify or light the burner 37. This may be accomplished in any suitable manner, and, in this 50 particular embodiment,a current is caused to flow through the solenoid 42 which closes the relay 43 and creates a current flow through the solenoid of the valve 4|. After the relay 43 has been closed, it remains closed, even after the arm 39 5 has disconnected from contact 40, because the relay 43 after it is closed maintains a current through solenoid 42 independently of the circuit through the arm 39 and contact 40 until such time as the contact arm 39 contacts with the 60. contact 44. This latter contact shorts the solenoid 42 through the resistance 45 and permits the relay 43 to drop or. open and thus close the valve 4|, extinguish or turn down the burner 31 and stop or reduce the concentrating action 65 in the tower H. A thermostat 4B is provided 76 By the construction shown, the concentration in the contact tower I! may be carried substantially to the crystallization point of the solution without danger of clogging; and thus the size of the concentrating portion of the apparatus can be materially reduced. When the apparatus is 5 shut down, the slight amount of liquid remaining inv the contact tower, after its automatic gravitational drainage into the sump 2|, may be allowed to cool and crystallize without danger of entirely closing the concentrating circuit. The crystals thus formed throughout the contact mass are not sumcient in size to clog all of the air or liquid passages and thus when the apparatus is restarted a partial flow is-permitted which quickly dissolves and removes the crystals from the tower. Thus all portions of the apparatus which contain liquid which' is likely to crystallize at normal atmospheric temperatures are automatically drained when the apparatus stops. If, on the other hand, the usual evaporator should be substituted for the tower M, then if the liquid should be concentratedsubstantially to the crystallization point in the evaporator, it would be necessary to drain the evaporator before shutting down the plant or the liquid in the evaporator would quickly crystallize when it cooled during the shut-down period and create a diflicult and dangerous restarting condition.

By this construction also it is not necessary to have a heat interchanger in the concentrating cycle between the liquids flowing to and from the evaporator. The necessity for such an interchanger is removed in my apparatus because the liquid flowing through the tower i1 is cooled v substantially to atmospheric temperature by the air at the bottom of the tower before the liquid returns into the sump 2L.

This method may be practiced for conditioning air or for removing a constituent from a gas. When it is used for conditioning air, the hygroscopic solution or liquid may be any of the liquids used for this purpose, such as solutions of CaClz, NaCl, LiNOz, NazSOa H2So4, and of the water soluble lithium halides, lithium chloride, lithium 45 bromide and lithium iodide and, other lithium salts which are halogen in their vapor pressure characteristics-.- Molten salts, such as LiNO5, H20, water soluble organic liquids, such as glycerine ethylene glycol, or solutions of organic substances, such as sugar, glucose may be used.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form,

it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as'followsz 7 1. Ali apparatus '01 the character described comprising means establishing a main body 01 liquid, means for contacting a portion of said liquid with a gashaving a constituent to be selectively removed by said liquid, means for circulating a second portion of said liquid from and to said body in a closed cycle, means for heating the liquid in said cycle out of contact with a gas, means for discharging the liquid thus heated ror gravitational flow in contact. with a gas for the removal of said constituent from said liquid, means for bleeding a third portion of liquidfrom said main body separate from said second portion, and means for automatically controlling the removal of said constituent from said second portion of said liquid in accordance with its proportion in said third portion 0! liquid.

2. An apparatus of the character described comprising means for establishing a main body of liquid, means for circulating a portion of said liquid from and to said body in a closed cycle, means for contacting the liquid in said cycle with a first gas having a constituent to be selectively removed by said liquid, means for circulating another portion of the liquid from and to said main body in another closed cycle, means for heating the liquid in said last named cycle, means for contacting the liquid thus heated witha second gas for the removal of said constituent from said liquid, and means for controlling the treatment of liquid in said last named cycle in accordance with a condition of the liquid in said main body of liquid and in accordance with the condition of said first gas.

3. An apparatus for conditioning air comprising a sump for a main body of hygroscopic liquid, an air contact apparatus for contacting a first stream of air to be conditioned, means for circulating hygroscopic liquid from said sump to said contact apparatus, a concentrating contact tower, means for heating hygroscopic liquid, flowing it gravitationally through said concentrating contact tower and delivering it to said; sump, means for flowing a second stream of air oppositely to said hygroscopic liquid through said concentrating contact tower, and means for automatically controlling the flow of hygroscopic liquid to said concentrating contact tower in accordance with conditions of the conditioned air.

4. An apparatus for conditioning air comprising a sump for a main body of hygroscopic liquid, an air contact apparatus for contacting a first stream of air to be conditioned, means for circulating hygroscopic liquid from said sump to said contact apparatus, a concentrating contact tower, means for heating hygroscopic liquid, flowing it gravitationally through said concentrating contact tower and delivering it to said sump, means for flowing a second stream of air oppositely to said hygroscopic liquid through said concentrating contact tower, and means for automatically controlling the flow of air through said contact apparatus in accordance with conditions of conditioned air.

5. An apparatus for conditioning air comprising a sump for a main body of hygroscopic liquid, an air contact apparatus for contacting a first stream of air to be conditioned, means for circulating hygroscopic liquid from said sump to said contact apparatus, a Concentrating contact tower, means for heating hygroscopic liquid, flowing it gravitationally through said concentrating contact tower and delivering it to said sump, means for flowing a second stream of air oppositely to said hygroscopic liquid through said concentrating contact tower, and means for automatically controlling the flow of air through said concentrating contact tower in accordance with conditions of conditioned air,

6. An apparatus of the character described comprising a tank to contain a main body of hygroscopic liquid, an air drying contact tower, a liquid concentrating tower, pumping means circulating liquid to and from said tank to and from said towers, air blower means forcing air through said towers, a closed liquid heater heating the liquid before discharge into said concentrating tower, and means for controlling the flow of liquid to said concentrating tower in accordance with conditions in the dried air and for controlling the temperature of liquid flowing to said concentrating tower in accordance with the concentration of liquid in said tank.

'7. An apparatus ,of the character described comprising a tank to contain a main body of hygroscopic liquid, an air drying contact tower, a liquid concentrating tower, pumping means circulating liquid to and from said tank to and from said towers, air blower means forcing air 'through said towers, a closed liquid heater heating the liquid before discharge into said concentrating tower, means for controlling the temperature of liquid flowing to said concentrating tower in accordance with the concentration of liquid in said tank, and means for controlling the flow of liquid to said concentrating tower in accordance with demands on the apparatus for dried air.

8. An air conditioning system comprising means forming a main body of hygroscopic liquid, an air conditioning tower connected with a space to be conditioned and having liquid flow connections with said main body, a liquid con-' centrating apparatus connected with said main body, pumping means causing flow from said main body to said tower and said concentrating apparatus, means responsive to conditions in the space to be conditioned controlling the operation of said air conditioning tower, means responsive to the concentration of the liquid controlling operation of said concentrating apparatus, and means preventing the operation of the concentrating apparatus except when said air conditioning tower is in operation.

9. An air conditioning system comprising means forming a main body of hygroscopic liquid, an air conditioning tower connected with a space to be conditioned and having liquid flow connections with said main body, a liquid concentrating apparatus connected with said main body, pumping means causing flow from said main body to said tower and said concentrating apparatus, means responsive to conditions in the space to be conditioned controlling the operation of said air conditioning tower, means con-.

trolling the operation of said liquid concentrating apparatus in accordance with the concentra- 

